The present invention relates generally to a method for producing authenticatable paper. More specifically, the present invention relates to a process for producing authenticatable paper and paperboard products by introducing into the papermaking furnish fibers to which there has been attached a fluorescent whitening agent (FWA) that is detectable using long wave UV illumination. Since FWA's are often used during the papermaking process to enhance the brightness of paper, it would be unlikely that a counterfeiter would recognize the use of an FWA in the paper as an authenticatable feature.
Traditionally, counterfeiting has been associated with the illicit production of currency. Today, however, there is a significant loss to manufacturers of goods by counterfeiting. This type of counterfeiting costs companies millions of dollars of lost revenue. For example, cigarette, pharmaceutical, computer software and related companies have experienced problems with counterfeited products being sold worldwide. Furthermore, these counterfeited products are usually made cheaply thereby causing an unsuspecting consumer to question the manufacturers' quality.
Thus it would be desirable, and in the best interest of a manufacturer to eliminate to the extent possible the sale of counterfeited products from an economic and public perception point of view. One way to accomplish this result is to provide packaging, labels and the like that can be authenticated for packaging the legitimate goods of a manufacturer.
Paper manufacturers have several different options at their disposal to authenticate paper products. These include the use of watermarks, specialized printing, holographic labels, and the use of synthetic or fluorescent fibers or additives. Thus packages which do not include these identifying features may be presumed to include counterfeited goods.
Watermarks consist of impressing a design into the wet fiber web prior to couching the paper. Since this process is done early in the papermaking process, it arranges some of the fibers within the paper. This arranging of the fibers makes watermarks difficult to duplicate.
Watermarks are used extensively in European and U.S. currencies and security documents. The security of the watermarking process may be enhanced with the controlled deposition of fibers during the paper forming process and the placing of individual, unique watermarks on each piece of paper.
The use of watermarks is ideally suited to the manufacture of thin papers such as currencies, bank checks, etc., which are substantially translucent. However, the use of watermarks on heavy weight paper or paperboard normally used for packaging or labels is of less utility because of the low transmission of light through such products. A watermark on these thicker papers would not be readily apparent as in thinner, more translucent papers.
Complicated printing techniques have also been used as security devices for currencies. These are typically lifelike portraits and intricate designs. Additionally, specialty inks, blended exclusively for these end uses, have found extensive use in the security document sector. These specialty inks include everything from using multiple colors, to the use of high intensity ultraviolet light to create a pattern fluorescing in visible or ultraviolet light. However, the advent of high quality, color photocopiers has made the use of special inks and intricate designs less of a barrier to the counterfeiter.
In response to the increased ingenuity of counterfeiters, microprinting was developed. Microprinting is a technique where messages, etc., are finely printed on a paper substrate. To the naked eye, the printing appears to be a single line, but under magnification, the messages may be revealed. This technique makes duplication of the paper substrate more troublesome because the printing technique is difficult to reproduce. However, a drawback to the microprinting technique is that it is relatively easy to acquire a printing press. Also, one can set up this printing equipment anywhere and keep it well hidden.
Holographic labels are also used as an anti-counterfeit device. These labels have an image impressed into them which changes appearance dependent on the point of view. A familiar example of these labels is the shiny image on credit cards. While these are effective as an anti-counterfeit device, they are expensive to produce and keep track of.
Placing dyed synthetic fibers into the paper substrate has been practiced for many years as an anti-counterfeit device. A common example is the paper used for U.S. currency which has blue and red synthetic fibers in it. Though effective, it has a significant drawback because it can only be used in specific applications.
Finally, it is also known to use fibers, pigments and the like in the structure of the paper products that can be identified using various techniques. For example, U.S. Pat. No. 1,938,543 teaches that detectable fibers which have been specially treated with a chemically sensitive substance can be incorporated into paper and, upon contacting such paper with a second chemical agent, the detectable fibers change color and become distinguishable. A disadvantage with this type of technique is that it is a destructive test. As illustrated in U.S. Pat. No. 2,208,653, authenticatable paper can also be made by including fibers of an organic ester of cellulose that have been treated with a tertiary amine. The treated fibers are invisible in the paper and become fluorescent under ultraviolet light. U.S. Pat. No. 2,379,443 discloses authenticatable paper made by the addition of a small percentage of cellulosic fibers that have been treated with hydrated ferric chloride which has been hydrolyzed to iron hydroxide. The treated fibers are capable of acquiring a deep blue color upon application to the paper of a potassium ferrocyanide solution, followed by an orthophosphoric acid solution.
Nevertheless, the authenticatable papers disclosed in the prior art generally have not proven entirely satisfactory because, for example, of their complexity of manufacture, or the fact that such papers before authentication often visibly differ from paper that does not include an authenticatable feature, or the procedure for testing is cumbersome.
It is apparent from the above that there exists a need in the art for an authenticatable paper or paperboard that is inexpensive to manufacture, effective in use, and hard to duplicate. Furthermore, the authenticatable materials used should not interfere with the print characteristics of the paper nor the coating operations. It is the purpose of this invention to fulfill these and other needs in the art in a manner more apparent to the skilled artisan once given the following disclosure.